1. Field of the Invention
The present invention relates to novel benzologs and to methods of producing benzologs.
2. Description of the Prior Art
Purinol-type compounds of the formula (V) ##STR2## wherein X.sup.1 and Y.sup.1 stand for hydroxy, mercapto, amino or hydrogen are known in the art; they are known to have biological activities and many of them are used in pharmacology. For example, the compound (A) wherein X.sup.1 is hydroxy and Y.sup.1 is hydrogen is the pyrazolo[3,4-d]pyrimidine-4-one known under the generic name Allopurinol. Since its first preparation more than two decades ago (cf. R. K. Robbins, J. Am. Chem. Soc. 78 (1956) 784) it has been used for therapeutical purposes as an inhibitor of xanthine oxidase and for its controlling effect upon the concentration of uric acid in human blood, e.g. for treatment of gout.
Allopurinol and related compounds of formula (V) as well as therapeutical uses of such compounds are disclosed, for example, in U.S. Pat. Nos. 3,624,205, 2,519,716 and 3,626,064 and in British Pat. No. 975,850. Typical related compounds are oxipurinol (formula V: both X.sup.1 and Y.sup.1 are hydroxy), aminopurinol (formula V: X.sup.1 is hydroxy, Y.sup.1 is amino), thiopurinol (formula V: X.sup.1 is mercapto, Y.sup.1 is hydrogen) and the like. In addition to, or instead of, xanthine oxidase inhibiting effect, such compounds of formula (V) have, or are believed to have, important antineoplastic and immunosuppressive effects and have, or may have, important clinical uses including therapy of cancer, e.g. human leukemia.
As set forth in our above mentioned U.S. application Ser. No. 968,577 now U.S. Pat. No. 4,223,143 Allopurinol has a relatively low solubility and must be used at a relatively high dosage level and it is believed that similar considerations would apply to the prior art compounds of formula (V) as a class. Accordingly, there is a need to find new compounds having a sufficient structural similarity with the formula (V) compounds to retain or increase their beneficial effects and/or to provide such formula (V)-related substances that have generally more favorable physiological and therapeutic effects than the formula (V) compounds proper.
Accordingly, it is a main object of this invention to provide for novel compounds that include the effective moieties of the formula (V) compounds in a modified structural arrangement.
A further object is to provide for purinol-related compounds for therapeutic use instead of, or in combination with, purinols.
Another object is a method of producing novel benzologs of formula (V) compounds as well as improved synthesis of previously disclosed benzologs.
Other objects will become apparent as the specification proceeds.